IMPROVEMENTS IN PHARMACEUTICAL CONTAINERS

Abstract: A bottomless pharmaceutical vial for filling, capping, and subsequent conversion into a syringe includes a shoulder (14) within its open bottom end (8) beneath a piston (10), and a retainer ring (20) snapped into engagement with the shoulder to retain the piston. The retainer ring has no part projecting beyond the external diameter of the vial, so that it may be installed prior to filling of the vial. A separate finger flange (32) may subsequently be snapped into place if required.

Description: IMPROVEMENTS IN PHARMACEUTICAL CONTAINERS This invention relates to pharmaceutical containers, more specifically bottomless pharmaceutical vials of the general character described in European Patent Application No. 0298585, and International Patent Application WO 92/08507. Such vials once filled and capped can be converted into prefilled syringes forming the basis of a wide range of pharmaceutical delivery systems. There is an increasing requirement for terminal sterilization of such bottomless vials and prefilled syringes, and even if the sterilization procedure is very carefully controlled using sophisticated equipment, there is a risk of pressure differentials being set up across the piston of the vial or syringe which may result in its expulsion. Such pressure differentials could alεo conceivably occur during storage, particularly in the case of vials containing large gas spaces or substances which may generate gases during storage. It has previously been proposed to provide piston retainer rings which interlock projections formed at or near the base of the vial, and which may also serve to provide a finger grip for a syringe formed from such a vial. It is however important that such projections do not interfere to any significant extent with either the stable passage of SUBSTITUTE SHEET vials through vial filling and capping machinery, nor with insertion of the piston into the vial body. They must also permit easy insertion of retainer rings and provide for their positive retention once inserted. Such an arrangement is described in WO 92/08507. A problem with this arrangement is that installation of the retainer rings must be effected between filling and capping of the vials and their terminal sterilization, which introduces a further manufacturing step that must be carried out under clean room conditions. I have now found that, by further development of the arrangement of WO 92/08507, it is possible to provide a retainer ring which can be inserted prior to filling and capping of the vial without interfering with passage of the vial through the machinery carrying out these operations. This means that prepared presterilized vials with both piston and retainer in place may be utilized in the filling and capping operation to provide an assembly ready for terminal sterilization without any additional operation or any requirement for retainer inserting machinery as part of the filling line. The present invention relates to an improved bottomless vial as set forth in the appended claims. Further features of the invention will be apparent from the following description with reference to the accompanying drawing, wherein: Figure 1 is a longitudinal section through the body of an embodiment of a bottomless vial, shown fitted with a piston retainer ring; and Figure 2 is a detail of the body shown in Figure 1, on an enlarged scale, and with an optional finger flange portion shown separated. Referring to Figures 1 and 2, a body 2 for a bottomless vial is moulded from glass or synthetic plastic material, with a generally cylindrical form having shoulders 4, at the top end connecting to a hollow neck 6. At a bottom end of the body its side wall is formed with a rounded or beaded bottom edge 8 to form an open bottom end through which a piston 10 may be inserted. A portion 16 of the inside side wall adjacent the bottom edge 8 is tapered inwardly and joined to the remainder of the side wall by a peripheral jog 12 so as to provide a narrow internal upwardly facing annular shelf or shoulder 14 above a funnel-shaped upwardly tapered bottom entry to the interior of the body. The shelf and tapered bottom entry may be formed by rolling a heat softened bottom portion of the wall against a suitably shaped mandrel, in which case the outer face of the wall will be recessed as shown at 18, or may be moulded in which case the outer recess may not be present. In either case, there will be no projection, or at least no significant projection, of the outer face of the moulded or rolled portion of the wall outside the circumference of the remainder of the wall. The tapered bottom entry assists in insertion of the piston 10, and subsequent insertion of the retainer ring 20 described below. The retainer ring 20 is moulded from synthetic plastic material and provided with a radially extending flange 22, and has a tapered upper portion 24 having a maximum diameter approximately equal to the internal diameter of the body 2 above the shelf 14, but greater than the internal diameter of the shelf, and a minimum diameter such that it can readily start to enter the tapered bottom entry to the body. A lower portion 26 of the ring above the flange 22 has a smaller external diameter and a height at least equal to the height of portion 16 so that the ring may be pressed into the tapered entry until a shoulder 28 between the upper and lower portions snaps over the shelf 14, thus positively retaining the ring. Preferably the lower portion 26 has an internal profile and height such as to provide snug accommodation of the portion 16 with due allowance for manufacturing tolerances. A small recess 30 may be formed in the inside wall of the body adjacent the shelf 14 to provide additional clearance for the shoulder 28. The flange 22 has a limited radial extent so that it does not extend beyond a projection of the external surface of the vial body. The retainer ring (20) may thus be inserted prior to filling and capping, but it cannot of itself also provide a finger flange. This problem can be overcome if a flange is required by providing a separately moulded flange 32, with an annular forwardly projecting locking ring 34 which can be snapped into annular groove 36 formed within the ring 20 prior to use of the vial. Such a separable finger flange also has the advantage that it may be fitted if the syringe is to be operated manually, but omitted if the syringe is to be used in a syringe pump, since many syringe pumps are unable to accommodate projection beyond the general external cylindrical surface of a syringe body, which has tended to limit their use to plastic syringes designed for such use.

Claims: CLAIMS : 1. A bottomless pharmaceutical vial for filling and capping prior to incorporation into a syringe, having a generally upright cylindrical hollow body (2) with a narrower filling neck (6) at its top end, a side wall of the body being formed with a bottom edge (8) surrounding a flared bottom opening, with an inner surface of a lower portion (15) of the side wall of the body adjacent said bottom opening extending upwardly to an outward jog in said inner surface, the jog forming an upwardly facing annular shoulder (14) , and no part of the lower portion of the side wall projecting appreciably outside an outside diameter of the remainder of the side wall, a piston (10) within the body, and a piston retainer ring (20) inserted into the bottom opening of the body beneath the piston, the piston retainer ring having an outer surface with an upper portion tapered to enter the flare of the inner wall of the body adjacent said bottom opening, a lower portion of reduced external diameter, a downwardly facing shoulder connecting said upper and lower outer face portions, such that the ring may be pressed into said bottom opening until the shoulder snaps over the shelf to retain the ring, characterized in that no part of the retainer ring (20) extends radially outwardly of the external diameter of the vial body. 2. A vial according to claim 1, characterized in that the retainer ring (20) includes a flange (22) extending beneath the bottom edge of the body but having a diameter no greater than that of the body. 3. A vial according to claim 1, characterized in that it includes a separately formed finger flange (32) for connection to the retainer ring (20) following filling and capping of the vial. 4. A vial according to claim 3, characterized in that the flange (22) has an internal peripheral groove, and a separately formed finger flange (32) is provided with a locking ring for subsequent engagement with the groove. 5. A syringe assembly including a vial according to any of claims 1 to 4.

Inventors: REYNOLDS DAVID L, REYNOLDS, DAVID, L.
Applicants: REYNOLDS DAVID L, REYNOLDS, DAVID, L.
Application year: 1994
Main classification: A61M5
IPC codes: A61J1, A61M5